This invention relates to sealing air gaps in the houses and commercial buildings to reduce energy loss due to air leakage through the gaps.
Many experts believe that 40% or more of energy loss in a home is due to air leakage. Some of that energy loss is due to wind, and some is due to the atmospheric pressure differences between the inside and the outside of the building. A significant portion of the air leakage is due to the xe2x80x9cchimney effectxe2x80x9d or the escape of rising heated air from the house into the attic. Air escapes through gaps that are virtually invisible, so few people even know that the gaps are present, let alone, how to seal the gaps. Specifically, there are gaps between the top plates of framed walls and the drywall that is installed against them. These gaps occur because of the imperfect fit and irregular size of the framing members. The gaps occur in all interior and exterior walls and on both sides of the interior walls. Since the gaps are often {fraction (1/16)}xe2x80x3-xe2x85x9xe2x80x3 or more in thickness, and may occur in literally hundreds of running feet of walls at the intersection with the attic, the net effect is a huge breach through which conditioned air escapes. Surprisingly, these gaps are virtually never sealed during the new home construction process. In fact, when typical new homes are tested with a Blower Door for air leakage, the volume of air lost through these spaces into the attic can be as much as 2 to 3 total air changes per day, or roughly equivalent to leaving a double hung window open 4 to 5 inches or more on a cold winter day. The attic insulation above these gaps provides no defense. In spite of the high xe2x80x9cR-valuexe2x80x9d of fiberglass, it does not stop air movement through it. Therefore, virtually every house in the U.S. was (and still is) built with pathways for continuous loss of air into the attic and covered with insulation that is ineffective in stopping the air movement.
Conventional methods employed to reduce this energy loss include dispensing an unshaped bead of caulk and allowing it to cure before the drywall is installed. This bead is highly ineffective since it becomes very rigid and creates wider voids than a wall without the bead. The bead is also objectionable to builders and drywall installers since it may not enable the desirable close fit of wallboards.
Another approach to seal gaps from the home into the attic is to apply a bead of mastic or standard caulking and to install the drywall before the bead hardens. However, this bead is often non-existent after the drywall is installed. When the drywall is slid up the wall and into position during installation, the leading edge of the drywall wipes away most of the sealant bead and it remains on the edge of the drywall (in a totally ineffective location) rather than behind the drywall where it needs to be. Attempts to change the installation habits of drywall hangers to preserve the bead have been unsuccessful. The installers claim that the drywall sheets are too heavy and awkward to gently place them against the wall, and then hold them steady long enough to nail them into position without disrupting an uncured bead of caulk.
Still another sealing method to seal gaps from the home into the attic is to use a commercially available foam tape or weather strip instead of the bead of caulk. However, this method is ineffective since the drywall doesn""t slide over the blunt edge of the weatherstrip tape. Instead the tape is sheared loose from the top plate by the drywall being slid into place and is never replaced. It is unreasonable to expect that a drywall Installer, being paid on a piece-work basis, would reattach every piece of weather strip that tears loose. In most cases, the tape simply xe2x80x9cdisappearsxe2x80x9d or remains on the leading edge of the drywall, and the homeowner is the loser, because the homeowner does not receive the energy saving device the owner thought he or she was buying.
Accordingly, there is a need to provide a method and structure to seal the air gaps in houses and commercial buildings to reduce the energy losses associated with air leaking through unsealed air gaps into the attic.
An object of the invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is obtained by providing a seal structure for sealing an air gap between a framing member and a wallboard. The seal structure is formed on site from a curable, flowable material and includes a body having first and second opposing surfaces. The first surface of the body is constructed and arranged to be bonded to the member. Two or three flexible seal members are integral with and extend generally transversely with respect to the second surface of the body. The seal members are disposed in spaced relation to define a double or triple seal between the framing member and the wallboard when the wallboard engages distal ends of the seal members.
Another object of the invention is to provide a method of sealing an airspace between a member and wallboard. The method includes placing a seal structure on the member. The preferred seal structure comprising an elongated body and two or three seal members integral with and extending generally transversely with respect to a surface of the body. The seal members are flexible and disposed in spaced relation. A wallboard is placed in contact with distal ends of the seal members to defined two or three seals between the wallboard and the member.
Yet another object of the invention is to provide a method of sealing an air gap between a member and a wallboard. The method includes spraying a flexible sealant under pressure into the air gap to fill the air gap.
Other objects, features and characteristic of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.